This invention relates to a radio-frequency (RF) penetrating probe electrode for treating tissue with radio frequency energy, commonly referred to as electrosurgery.
Our copending U.S. application Ser. No. 09/303,839, whose contents are hereby incorporated by reference, describes apparatus for use in a surgical procedure commonly known as minimally invasive surgery (MIS), for treating, say, a herniated disk to remove undesired regions and to provide controlled heat to shrink the tissue during surgery. The electrode for MIS use is preferably constructed with a flexible end controllable by the surgeon so as to allow the surgeon to manipulate the end as desired during the surgical procedure.
This tissue-shrinking concept has recently been extended to the treatment of other disorders. It is sometimes known as Radio Frequency Thermal Ablation (RFTA), which uses radio frequency (RF) heating to create targeted tissue ablation resulting in tissue volume reduction. One proposed application, described in a paper published in Kania, Sep. 25, 1999 by Pr. B. Meyer, is for the treatment of Obstructive Sleep Apnea Syndrome (OSAS) and more generally sleep disordered breathing (SDB). The proposed procedure is to insert a pointed electrode into the tongue base below the uvula and apply RF energy such that resistive heating of the tissue occurs, raising the temperature of the immediately surrounding tissue to a temperature that damages or kills the cells. This produces a small lesion which is later replaced by scar tissue and removed by the body, resulting in the shrinkage or volumetric reduction of the treated tissue. This procedure by reducing the volume of the local tissue may enlarge the airway alleviating SDB.
Present electrosurgical probes used for penetration of tissue for subcutaneous tissue reduction are typically round and generally terminate in an elongated thin tip portion which is inserted into and through tissue, such as, mucosal tissue, muscle epidermis, dermis, tonsil, turbinate, or tongue tissue. After the probe tip reaches the desired target area, RF electrosurgery energy passes through the probe to submucosaly create a lesion to shrink, ablate and volumetrically reduce the soft palate, tonsil, turbinate, uvula, or tongue, respectively. Our copending U.S. application Ser. No. 09/442,316, whose contents are hereby incorporated by reference, describes a generally L-shaped electrode for implementing RFTA, especially for tongue blade tissue. The electrode used has a round shape with a pointed end and a main feature is the addition of measured color-coded shaft sections for assisting the surgeon in determining needle pentration depth.
The use of the existing RF penetrating probes of this type is their inherent limitation and difficulty in penetration and moving through different tissue layers. The RF tissue reduction procedure with the existing probes slows down the procedure time. There is a loss of maneuverability, additional pre-operative pain to the patient due to the slow movement insertion through the tissue layers. The use of these existing probe designs produce a substantial amount of unnecessary pain and trauma to the patient. Other problems that often occur with the existing RF round probes is that, due to their elongated thin tip insertion portion, the tissue entry opening is wider causing additional trauma. Additionally, existing probes due to their poor design require unnecessary force to penetrate tissue.
An object of this invention is a new and useful improvement in the traditional electrosurgical probe of the type used for volumetric subcutaneous tissue reduction.
Another object of the invention is a new RF probe design that provides greater maneuverability, that speeds up the procedure time producing less trauma and pain to the patient, and that is less fatiguing for the surgeon.
In accordance with a feature of the present invention, an RF penetrating probe is changed from a round diameter with sharpened thin point to an angled shape which provides a sharper edge on the side or sides of the needle allowing it to create a much smaller hole upon penetration, requiring less force to develop the initial hole in the tissue, and less force to move through the tissue layers. The angled probe of the invention also concentrates the RF energy more efficiently and precisely, with the result that the RF energy radiosurgical apparatus can be lowered in wattage and in time to produce the desired subcutaneous volumetric tissue reduction effect.
In accordance with a further feature of the present invention, the RF penetrating probe has a tapered distal end that reduces to a point, but that tapered distal end has a triangular or rectangular cross-section with the edges forming the triangular or rectangular cross-section extending parallel to the long axis of the distal end and being sharpened.
Among the benefits of the present invention is that the novel electrode can be used with low voltage, low power electrosurgical apparatus for the purpose of implementing RFTA with a relatively simple, easily learned procedure.
As with the tongue base electrode of the copending application, the electrode may be a generally L-shaped metal member comprising an electrically-insulated, generally straight shank part for mounting in a standard electrosurgical handpiece, a generally needle-shaped part which is electrically-insulating, and which, as the active section, is bare and terminates in a pointed end, and with the angled sides. The shaft portion preceding the bare active end may incorporate the invention of the copending application and thus be divided into several sections that are dimensioned and constructed so as to enable the surgeon to know fairly precisely the depth of the active section in the targeted tissue.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there are illustrated and described the preferred embodiments of the invention, like reference numerals designating the same or similar elements.